How I turned a tucked-away Mini ITX PC into a rack-friendly DIY NAS with Proxmox, Home Assistant OS, Plex, and a suite of containers

You’ve probably heard that a high-performance NAS requires pricey hardware and purpose-built chassis. The truth about a DIY NAS is a little simpler and a lot more accessible: repurposing an aging Mini ITX machine can yield a reliable, flexible home server that fits behind a closet door or in a shallow rack. In my case, I upgraded to a new PC but kept the old 5600X Mini ITX box—not to collect dust, but to become the backbone of a compact, rack-mable home NAS. I did it with a shelf, some drilled holes, and a handful of stand-offs. The result isn’t glamorous, but it’s incredibly practical: Proxmox running Home Assistant OS, Plex, Sonarr/Radarr/Overseerr, and a bunch of LXC containers.

If you’re eyeing a project like this, you’re already past the “will it work?” moment. You’re asking: what’s the best way to repurpose old hardware into a DIY NAS that’s quiet, power-conscious, and easy to manage? The short answer: you don’t need a twelve-thousand-dollar chassis. You need a plan, a clean way to mount things in a tight space (my cabinet depth was less than 450mm), and the right software stack. That’s where Proxmox shines, because it gives you virtual machines and containers in one place, with snapshots, backups, and a straightforward upgrade path.

In this post you’ll learn how I approached a DIY NAS with practical steps, the trade-offs I faced, and concrete actions you can copy. I’ll share the hardware layout, why I chose Proxmox over a pure Docker stack, and how I organized services like Home Assistant OS, Plex, and a string of media/personal-app containers.